3928071
Pregunta 1
Pregunta
How is the order of nucleotides in mRNA used to generate the linear sequences of amino acids in protein?
Respuesta
-
process known as translation
-
process know as transcription
-
process know as post translational modifications
Pregunta 2
Pregunta
What process is the most highly conserved across all organism and the most energetically costly?
Respuesta
-
translation
-
transcription
-
cellular respiration
Pregunta 3
Pregunta
Transcription is a more formidable challenge than translation.
Respuesta
- True
- False
Pregunta 4
Pregunta
The hydrophobic side chains of phenylalanine, tyrosine, and tryptophan forms interactions with the mRNA template.
Respuesta
- True
- False
Pregunta 5
Pregunta
Crick proposed a [blank_start]special adaptor[blank_end] molecule that directly interacts with the coding units of mRNA. He proposed to also be a [blank_start]RNA[blank_end] molecule.
Respuesta
-
RNA
-
special adaptor
Pregunta 6
Pregunta
amino acids that are attached to a class of RNA molecules that represent 15% of all celluar RNA and transfer amino acids to a growing polypeptide chain.
Respuesta
-
tRNA
-
rRNA
-
mRNA
Pregunta 7
Pregunta
The translation machinery is comprised of ?
Respuesta
-
mRNAs
-
tRNAs
-
aminoacyl-tRNA synthetases (aaRS)
-
ribosome
-
rRNA
-
DNA
Pregunta 8
Pregunta
The competent of the translation machinery are always discarded after use.
Respuesta
- True
- False
Pregunta 9
Pregunta
Provides the information to be interpreted by translation machinery
Respuesta
-
DNA
-
mRNA
-
amino acids
Pregunta 10
Pregunta
This region of the mRNA specifies the order of amino acids by the ordered series of 3-nucleotide-long units called codons?
Respuesta
-
introns
-
poly A tail
-
protein coding region
Pregunta 11
Pregunta
couple amino acids to specific tRNAs that recognize the appropriate codon?
Respuesta
-
ribozymes
-
aminoacyl tRNA synthetase
-
poly-a-polymerase
Pregunta 12
Pregunta
coordinates correct recognition of mRNA by each tRNA and catalyzes peptide bond formation between growing peptide chain and amino acids attached to tRNA
Respuesta
-
ribosomes
-
ribozymes
-
transferase
Pregunta 13
Pregunta
in mRNA containing 2 or more open reading frames that can encode for multiple polypeptide chains
Respuesta
-
eukaryotic
-
prokaryotic
Pregunta 14
Pregunta
protein coding regions of each mRNA is composed of contiguous, non-overlapping string of codons called?
Respuesta
-
protein coding region
-
origin of replication
-
ORF
Pregunta 15
Pregunta
Eukaryotes, contain a single ORF that encode for multiple protein which is called polycistronic.
Respuesta
- True
- False
Pregunta 16
Pregunta
translation starts at the [blank_start]5'[blank_end] end of ORF and proceeds into the 3' end
Respuesta
-
5'
-
3'
Pregunta 17
Pregunta
Start codons in bacteria
Respuesta
-
AUG
-
GUG
-
UUG
-
UAA
-
UGA
Pregunta 18
Pregunta
eukaryotic cells always use AUG as a stop codon
Respuesta
- True
- False
Pregunta 19
Pregunta
fundamental unit of an ORF is a [blank_start]codon[blank_end]
Respuesta
-
codon
Pregunta 20
Pregunta
What are the important functions of a start codon?
Respuesta
-
specify first amino acid incorporation
-
contains special interactions with tRNA for protein synthesis
-
defines the reading frame for all subsequent codons
-
allows for hydrogen bonding to other bases
Pregunta 21
Pregunta
Since the codons are a 3-nucleotide long, any stretch of mRNA could be translated in three different reading frames by overlapping.
Respuesta
- True
- False
Pregunta 22
Pregunta
Stop codons are UAG,UGA and UAA in both eukaryotes and prokaryotes
Respuesta
- True
- False
Pregunta 23
Pregunta
Eukaryotic mRNA recruit ribosomes by the shine-dalgarno sequence which is ribosome binding site(RBS) that recruit the translation machinery.
Respuesta
- True
- False
Pregunta 24
Pregunta
the ribosome binding site
Respuesta
-
binds with the 16s rRNA of the ribosome
-
has a sequnce of CCUCCU
-
always has poor spacing
-
in all prokaryote has strong binding
Pregunta 25
Pregunta
limited complementarity and poor spacing promotes active translation
Respuesta
- True
- False
Pregunta 26
Pregunta
some prokaryotes lack a strong RBS but can still be actively translated by having a start and a stop codon right next to each other.
Respuesta
- True
- False
Pregunta 27
Pregunta
who uses their 5' and 3' modified ends to facilitate translation?
Respuesta
-
bacteria
-
prokaryotes
-
eukaryotes
Pregunta 28
Pregunta
Kozak sequence
Respuesta
-
a purine, three bases upstream of the start codon and a guanine downstream
-
extreme 5' end
-
presence
-
scanning
-
interacts with initiator tRNA
Pregunta 29
Pregunta
5' cap allows the ribosome to be recruited in order to go through a process called scanning.
Respuesta
- True
- False
Pregunta 30
Pregunta
[blank_start]poly-A-tail[blank_end] at the end of mRNA enhances the level of translation of mRNA by promoting efficient recycling of [blank_start]ribosomes[blank_end].
Respuesta
-
poly-A-tail
-
ribosomes
Pregunta 31
Pregunta
[blank_start]tRNA[blank_end] molecules are 75 to 95 ribonucleotides in length which there are many types of.
Respuesta
-
tRNA
Pregunta 32
Pregunta
The site at which amino acid is attached by the enzyme aminoacyl tRNA syntheses?
Respuesta
-
D loop
-
5'CCA3'
-
anticodon loop
-
TYC loop
Pregunta 33
Pregunta
Unusual bases found in tRNAs primary structure created by post-transcriptional modifications?
Respuesta
-
pseudouridine
-
dihydrouridine
-
hypoxanthine
-
uridine
Pregunta 34
Pregunta
principle features of the tRNA clover leaf are
Respuesta
-
acceptor stem
-
YU loop
-
D loop
-
anticodon loop
-
constant loop
-
variable loop
Pregunta 35
Pregunta
L-shape reveals the secondary structure of tRNA, which is stabilized by hydrogen bonds only.
Respuesta
- True
- False
Pregunta 36
Pregunta
charged tRNAs have an amino acid attached to them by amino alkyl linkage
Respuesta
- True
- False
Pregunta 37
Pregunta
acyl linkage is a high energy bond that is hydrolysis results in a large change in free energy, which helps drive the formation of peptide bonds
Respuesta
- True
- False
Pregunta 38
Pregunta
step one of aminoacyl-tRNA charging is [blank_start]adenylyation[blank_end] which amino acid reacts with ATP, amino acid is attached to adenylic acid via group transfer ester bond.
Respuesta
-
adenylyation
Pregunta 39
Pregunta
Whats the driving force that make adenylaltion energetically favorable reaction?
Respuesta
-
the release of pyrophosphate (PPI)
-
hydrolysis of pyrophosphate (PPi)
Pregunta 40
Pregunta
In step two of aminoacyl tRNA-charging- the adenylylated amino acid which is highly bound to the synthetase reacts with?
Respuesta
-
tRNA
-
PPI
-
another amino acid
Pregunta 41
Pregunta
Class 2 tRNA syntheses enzyme attach the amino acid to the 2'OH of the tRNA and are generally monomeric.
Respuesta
- True
- False
Pregunta 42
Pregunta
each aminoacyl tRNA synthetase attaches a single amino acid to only one tRNA which is know as isoaccepting tRNAs.
Respuesta
- True
- False
Pregunta 43
Pregunta
most organism have 20 different tRNA synthetase
Respuesta
- True
- False
Pregunta 44
Pregunta
tRNA structure that determine recognition by specific aminacyl tRNA synthetases?
Respuesta
-
acceptor stem and discriminator base
-
D loop
-
anticodon loop
-
variable loop
Pregunta 45
Pregunta
Why does aminoacyl-tRNA synthetase face a challenge in selecting the correct amino acid?
Respuesta
-
small size
-
side chains
-
similarity
Pregunta 46
Pregunta
There is more proofreading after the aminoacyl-tRNA synthetase has used its editing pocket to charge tRNAs with low accuracy.
Respuesta
- True
- False
Pregunta 47
Pregunta
when cysteinyl-tRNA ^cys converted to alanine-tRNA^ cys ( by reduction) and added to a cell free protein synthesizing system, alanine-tRNA^cys introduces alanines at the codons that are suppose to be cysteine. why?
Respuesta
-
ribosomes recognize tRNA not amino acid that its carrying
-
wrong tRNA has been incorporated
-
the tRNA is isoaccepting therefore can carry more than one amino acid
Pregunta 48
Pregunta
Eukaryotes can commence translation of the mRNA as it emerges from the RNA polymerase because the transcription machinery and the translation machinery are in the same compartment.
Respuesta
- True
- False
Pregunta 49
Pregunta
The ribosome is made up of large subunit which contains the [blank_start]peptidase transferase center[blank_end] and the small subunit that contains the [blank_start]decoding center[blank_end].
Respuesta
-
decoding center
-
peptidase transferase center
-
30S
-
50S
Pregunta 50
Pregunta
polysomes are
Respuesta
-
mRNA with multiple ribosomes
-
spaced 80 nt apart
-
polyribosomes
-
happen in eukaryotes
-
happen in prokaryotes
Pregunta 51
Pregunta
When small and large subunits undergo of the ribosome associate with each other and the mRNA, translate the target mRNA, then dissociate after each round of sythesis.
Respuesta
-
ribosome cycle
-
sedimentation by centrifugation
-
polysome
Pregunta 52
Pregunta
translation occurs
Respuesta
-
from 5' to 3'
-
from N terminal to C-terminal
-
by attaching new amino acid to the C-terminus of a growing polypeptide chain
Pregunta 53
Pregunta
substrate(s) for a round of amino acid addition are
Respuesta
-
2 charged species of tRNA
-
1 charged species of tRNA
Pregunta 54
Pregunta
The bond between the aminoacyl-tRNA and the amino acid is not broken during the formation of the next peptide bond.
Respuesta
- True
- False
Pregunta 55
Pregunta
What drives the peptide bond formation?
Respuesta
-
simultaneous hydrolysis of nucleoside triphosphate
-
breaking the high energy acyl bond that joins the growing polypeptide chain to the tRNA
Pregunta 56
Pregunta
ribosomal RNAs are represent the main component of the ribosome because
Respuesta
-
are located in the interior of the ribosome
-
essential for the peptidyl transferase reaction and binding the anticodon loop of tRNAs
-
are larger then proteins
-
protein stable rRNA by shielding negative charges of their sugar phosphate backbones
Pregunta 57
Pregunta
what are the three binding sites for tRNA on a ribosome
Respuesta
-
A site
-
D site
-
Enter site
-
P site
-
E site
Pregunta 58
Pregunta
peptidyl transferase center
Respuesta
-
formed by 20 nucleotides of 23s RNA
-
the 3'OH group of the tRNA in the P site is critical for activity and assist a concerted proton transfer
-
orients tRNAs in optimal proximity for peptidyltransferase rxn to occur
Pregunta 59
Pregunta
what allows only unpaired RNA to pass through the small and large subunit of the ribosome?
Respuesta
-
entry and amino channel
-
exit and adjacent channel
-
entry and exit channel
Pregunta 60
Pregunta
[blank_start]Entry[blank_end] channel is through the small subunit which is only wide enough to let unpaired mRNA through and too narrow for a [blank_start]secondary[blank_end] structure. Ensures that codons in mRNA will be exposed and available for pairing with the anticodon loops of tRNA.
Respuesta
-
Entry
-
secondary
Pregunta 61
Pregunta
the kink in the mRNA between two codons are included after ribosome translocation to not allow any entry of the mRNA
Respuesta
- True
- False
Pregunta 62
Pregunta
[blank_start]Exit[blank_end] channel lets nascent polypeptide through. Some secondary structures can form inside but some can't. But [blank_start]tertiary[blank_end] and quaternary structure will not be formed until after its exit the ribosome.
Respuesta
-
Exit
-
tertiary
Pregunta 63
Pregunta
Successful initiation in translation occurs when?
Respuesta
-
ribosome is recruited to the mRNA
-
ribosome placed over the start codon
-
charged tRNA placed into P site
-
tRNA goes through hydrolysis
Pregunta 64
Pregunta
translation initiation in prokaryotes is mostly done in the absence of the full ribosome
Respuesta
- True
- False
Pregunta 65
Pregunta
Specialized charged tRNA that binds directly to the P site and not the A site during initiation.
Respuesta
-
met-tRNA
-
initiator tRNA
-
charged tRNA
Pregunta 66
Pregunta
One of the three initiation factors, that binds to the small subunit and block its from reassociating with the large subunit or from binding charged tRNAs.
Respuesta
-
IF3
Pregunta 67
Pregunta
purple-one of the three initiation factors in prokaryotes, it is a GTAPase which interacts with IF 1, charged initiator tRNA, and the small subunit.
yellow-prevents tRNAs from binding to the portion of the small subunit that will become part of the A site.
Respuesta
-
IF 1
-
IF 4
-
IF 3
-
IF2
Pregunta 68
Pregunta
the last step in initiation is the 70s initiation complex, where fmet-tRNA, start codon, base pair which allows the small subunit to undergo a conformational change.
Respuesta
- True
- False
Pregunta 69
Pregunta
In eukaryotic initiation, the 43s pre-initiation complex
Respuesta
-
1A attaches at the exit site
-
Met-tRNA^met is bound to e1F3
-
EIF1,3,5 are bound to the exit site
-
the initiation factors attach to the 40s ribosome
Pregunta 70
Pregunta
recognition of eukaryotic mRNAs after 43S pre initiation complex,
Respuesta
-
recognition of 5' cap mediated by 3 subunits
-
recognition is mediated by a 3 subunit protein that specifically binds to RNA
-
unstructured mRNA recruits the 43S pre initiation complex to mRNA by eIF4F and eIF5
Pregunta 71
Pregunta
once the complex is assembled at the 5' end of the mRNA, they move along the 5'-3' direction by a process that ATP-dependent
Respuesta
-
eIF4F-associated RNA helices
-
finding the start codon
-
base pairing of the anticodon
Pregunta 72
Pregunta
The reason why the initiator tRNA must bind to the small subunit before it binds to the mRNA is because it is used in scanning by recognizing the start codon through base pairing between anticodon of tRNA and start codon.
Respuesta
- True
- False
Pregunta 73
Pregunta
The binding of the large subunit to the small subunit in eukaryotes
Respuesta
-
releases initiation factors by GTP hydrolysis
-
FMet-tRNA is placed in the P site of the 80s initiation complex
-
start codon and initiator tRNA in the P site is now ready to accept charged tRNAs
Pregunta 74
Pregunta
Poly-A-binding protein and eIF4G interact by the 5' and 3' end of the mRNA to
Respuesta
-
make mRNA linear
-
stabilize mRNA (exonucleases)
-
decrease efficiency of translation
-
helps recycling ribosomes
Pregunta 75
Pregunta
Exceptions to eukaryotic polypeptide being encoded by an open reading frame that starts with AUG?
Respuesta
-
internal ribosome entry sites
-
eIF3
-
uORF
Pregunta 76
Pregunta
eIF4G adaptor role when an mRNA is capped?
Respuesta
-
eIF4G directly binds to IRES
-
eIF4G binds to poly A tail
-
eIF4G serves as an adaptor between the pre initiation complex and the EIF4E bound to it
Pregunta 77
Pregunta
Elongation is very different in prokaryotes and eukaryotes.
Respuesta
- True
- False
Pregunta 78
Respuesta
-
translocation
Pregunta 79
Pregunta
When EF-Tu is bound to GDP and lacking any bound nucleotide it shows high affinity for aminoacyl-tRNAs.
Respuesta
- True
- False
Pregunta 80
Pregunta
What are one of the three mechanisms that contributes to the fidelity of codon recognition?
Respuesta
-
two adjacent adenine residues in 16S
-
ATP hydrolysis
Pregunta 81
Pregunta
Third mechanism in correct codon-anticodon incorporation is [blank_start]accommodation[blank_end], which is rotation of tRNA into the peptidyl transferase center.
Respuesta
-
accommodation
-
GTP hydrolysis
Pregunta 82
Pregunta
Reason why ribosome is a ribozyme?
Respuesta
-
23s RNA
-
proteins
-
aminoacyl-tRNA
Pregunta 83
Pregunta
23S rRNA catalyzes peptide bond formation by base pairing with the CCA variable loop of the tRNAs in the A and the P sites with help position alpha amino go of aminoacyl tRNA to attack carbonyl of growing peptide attached to peptidyl-tRNA.
Respuesta
- True
- False
Pregunta 84
Pregunta
[blank_start]EF-G[blank_end] is an elongation factor that completes translocation by binding to the ribosome's factor binding center with GTP.
Respuesta
-
EF-G
-
EF-Tu
Pregunta 85
Pregunta
[blank_start]molecular mimicry[blank_end] in which a protein takes on the appearance of a tRNA to facilitate association with the same binding site.
Respuesta
-
molecular mimicry
-
all elongation factor
Pregunta 86
Pregunta
Exchange of GDP for GTP for both EF-TU-GDP and EF-G-GDP are? ( in order)
Respuesta
-
GDP release and binds to new GTP, exchanging GDP for GTP by complex
-
exchanging GDP for GTP by complex, GDP release and binds to new GTP,
Pregunta 87
Pregunta
Eukaryotic factors analogous to EF-Tu ([blank_start]eEF1[blank_end]) and EF-G([blank_start]eEF2[blank_end]) are name differently but have similar function.
Respuesta
-
eEF1
-
EIF1A
-
eEF2
-
EF-Tu
Pregunta 88
Pregunta
how many molecules of ATP and GTP are used for peptide bond formation?
Respuesta
-
2 ATP and 1 GTP
-
2GTP and 1 ATP
-
3 ATP and 0 GTP
Pregunta 89
Pregunta
Termination of translation is done by
Respuesta
-
RF1: recognizes UGA
-
release factors
-
RF2: recognizes UGA
-
eRF1
Pregunta 90
Pregunta
the name of the codon on the release factor the recognizes a stop codon?
Respuesta
-
anticodon
-
peptide anticodon
-
GGQ
Pregunta 91
Pregunta
Class II release factor RF3,
Respuesta
-
has higher affinity for GDP than GTP
-
conformational change in ribosome, the class 1 RF stimulates GDP to GTP exchange
-
No class 1 RF, RF-3-GDP has high affinity for ribosome
Pregunta 92
Pregunta
RRF
Respuesta
-
ribosome recycling factor
-
mimics tRNA
-
works with EF-G and IF3
Pregunta 93
Pregunta
Puromycin is an aminoglycoside antibiotic which binds to the 16rRNA causing misreading of the genetic code
Respuesta
- True
- False
Pregunta 94
Pregunta
tetracycline is a polyketide, which block the p site.
Respuesta
- True
- False
Pregunta 95
Pregunta
puromycin
Respuesta
-
mimics aa-tRNA
-
used for cleaning purposes
Pregunta 96
Pregunta
SsrA
Respuesta
-
in prokaryotes
-
initiation factor
-
tmRNA (tRNA/mRNA
Pregunta 97
Respuesta
-
non-stop mediated decay
-
nonsense mediated mRNA decay
Pregunta 98
Respuesta
-
nonstop mediated decay
-
nonsense mediated mRNA decay
Pregunta 99
Pregunta
protein mediated regulation in bacteria
Respuesta
-
inhibition of 30s initiation complex binding
-
secondary structure of mRNA can inhibit translation initiation
Pregunta 100
Pregunta
riboswitches are
Respuesta
-
RNA sensors for regulation of translation
-
binding to its own mRNA
Pregunta 101
Pregunta
regulation of translation by small RNA (sRNA) in bacteria
Respuesta
-
eIF2
-
Hfq
Pregunta 102
Pregunta
initiation in eukaryotic translation is globally regulated by
Respuesta
-
rapamycin
-
eIF4G
-
elF4E-binding proteins
Pregunta 103
Pregunta
gene specific regulation of translation through cap sequestration in eukaryotes
Respuesta
- True
- False
Pregunta 104
Pregunta
Iron regulation is mediated by amino acids acting as sensor via steric hinderance
Respuesta
- True
- False
Pregunta 105
Pregunta
[blank_start]Translation[blank_end] of GCN4 is controlled by short upstream ORFs.
Respuesta
-
Translation
-
upregulation
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